Circulating microRNA miR-323-3p as a biomarker of ectopic pregnancy

Ectopic pregnancy, its potential links to dementia risk and interactions with depression: insights from a nationwide cohort study

Background

Dementia poses a growing global mental health impact, with variations in prevalence by gender, possibly influenced by reproductive factors. Ectopic pregnancy (EP), known for its association with cardiovascular diseases and depression, which are also predictors of dementia, prompted an exploration of their interplay.

Methods

Using Taiwan's National Health Insurance Research Database, this nationwide cohort study examined 53,096 individuals to investigate the link between EP and dementia. Covariates included age, insured premiums, comorbidity by Charlson Comorbidity Index revised by excluding dementia, level of care, and residence. Surgical approaches, number of EP episodes, and dementia subtypes were considered in outcomes analysis using Cox regression.

Results

Among 13,274 women diagnosed with EP, 791 developed dementia over a 15-year follow-up, particularly vascular dementia. Adjusting for the covariates, the adjusted sub-distribution Hazard Ratio (asHR) with competing risks was 1.644 (95% CI, 1.394-2.053; p < 0.001). For patients with more than one episode, it was even higher (asHR=1.670 [95% CI, 1.419-2.092; p < 0.001]). Post-ectopic depression, prevalent in 62.2% within four weeks, was associated with a greater dementia risk compared to those without (asHR=1.702 [95% CI, 1.444-2.125; p<0.001] vs. asHR=1.551 [95%CI, 1.310-1.937; p<0.001]). Antidepressant treatments showed a partial protective effect, reducing the increased risk by 14.7%.

Conclusion

An EP history is linked to an earlier onset and a higher risk of overall dementia, VaD in particular, in a dose dependent manner, regardless of surgical intervention and stroke. Post-ectopic depression exacerbates dementia risk, while antidepressants offer partial protection. These findings underscore the potential benefit of screening and treating depression in women following EPs.

Diagnostic Value and Molecular Function of MicroRNAs in Endometrial Diseases: A Systematic Review

The human endometrium experiences significant cyclic morphological and biochemical changes throughout the menstrual cycle to prepare for embryo implantation. These processes are meticulously regulated by ovarian steroids and various locally expressed genes, encompassing inflammatory reactions, apoptosis, cell proliferation, angiogenesis, differentiation (tissue formation), and tissue remodeling. MicroRNAs (miRNAs) have been recognized as crucial regulators of gene expression, with their altered expression being linked to the onset and progression of various disorders, including cancer. This review examines the expression of miRNAs in the endometrium and their potential regulatory roles under pathological conditions such as endometriosis, recurrent implantation failure and endometrial cancer. Given miRNAs' critical role in maintaining gene expression stability, understanding the regulatory mechanisms of endometrial miRNAs and identifying their specific target genes could pave the way for developing preventive and therapeutic strategies targeting specific genes associated with these reproductive disorders.

Diagnostic utility of clinicodemographic, biochemical and metabolite variables to identify viable pregnancies in a symptomatic cohort during early gestation

A significant number of pregnancies are lost in the first trimester and 1-2% are ectopic pregnancies (EPs). Early pregnancy loss in general can cause significant morbidity with bleeding or infection, while EPs are the leading cause of maternal mortality in the first trimester. Symptoms of pregnancy loss and EP are very similar (including pain and bleeding); however, these symptoms are also common in live normally sited pregnancies (LNSP). To date, no biomarkers have been identified to differentiate LNSP from pregnancies that will not progress beyond early gestation (non-viable or EPs), defined together as combined adverse outcomes (CAO). In this study, we present a novel machine learning pipeline to create prediction models that identify a composite biomarker to differentiate LNSP from CAO in symptomatic women. This prospective cohort study included 370 participants. A single blood sample was prospectively collected from participants on first emergency presentation prior to final clinical diagnosis of pregnancy outcome: LNSP, miscarriage, pregnancy of unknown location (PUL) or tubal EP (tEP). Miscarriage, PUL and tEP were grouped together into a CAO group. Human chorionic gonadotrophin β (β-hCG) and progesterone concentrations were measured in plasma. Serum samples were subjected to untargeted metabolomic profiling. The cohort was randomly split into train and validation data sets, with the train data set subjected to variable selection. Nine metabolite signals were identified as key discriminators of LNSP versus CAO. Random forest models were constructed using stable metabolite signals alone, or in combination with plasma hormone concentrations and demographic data. When comparing LNSP with CAO, a model with stable metabolite signals only demonstrated a modest predictive accuracy (0.68), which was comparable to a model of β-hCG and progesterone (0.71). The best model for LNSP prediction comprised stable metabolite signals and hormone concentrations (accuracy = 0.79). In conclusion, serum metabolite levels and biochemical markers from a single blood sample possess modest predictive utility in differentiating LNSP from CAO pregnancies upon first presentation, which is improved by variable selection and combination using machine learning. A diagnostic test to confirm LNSP and thus exclude pregnancies affecting maternal morbidity and potentially life-threatening outcomes would be invaluable in emergency situations.

Therapeutic Potential of Mesenchymal Stem Cells in PCOS

Polycystic ovary syndrome (PCOS) is a major reproductive endocrine disorder affecting different facets of a woman's life, comprising reproduction, metabolism, and mental health. Recently, several research groups have brought attention to the therapeutic capacity of mesenchymal stem cells (MSCs) for the treatment of female reproductive disorders. It is highlighted that the treatment with bone marrow mesenchymal stem cells (BMMSCs) considerably diminishes the levels of some inflammatory markers as well as essential genes for ovarian production of androgens, which are considerably higher in theca cells of PCOS women than in those of healthy cases. In addition, studies show that BMMSCs improve in vitro maturation (IVM) of germinal vesicles (GVs) and the number of antral follicles while lessening the number of primary and preantral follicles in mice with PCOS compared to healthy controls. Regarding adipose- derived mesenchymal stem cells (AdMSCs), these cells restore the ovarian structure, enhance the number of oocytes and corpora luteum, and diminish the number of aberrant cystic follicles in PCOS rats. Some research also indicates that umbilical cord mesenchymal stem cells (UC-MSCs) alleviate the inflammation of granulosa cells in women with PCOS. Therefore, due to the limited research on MSC therapy in PCOS, in this review, we summarize the current knowledge on the therapeutic potential of three types of MSCs: BMMSCs, AdMSCs, UC-MSCs and their secretome in the treatment of PCOS.

Nanomedicines for Improved Management of Ectopic Pregnancy: A Narrative Review

Ectopic pregnancy (EP) - the implantation of an embryo outside of the endometrial cavity, often in the fallopian tube - is a significant contributor to maternal morbidity and leading cause of maternal death due to hemorrhage in first trimester. Current diagnostic modalities including human chorionic gonadotropin (hCG) quantification and ultrasonography are effective, but may still misdiagnose EP at initial examination in many cases. Depending on the patient's hemodynamic stability and gestational duration of the pregnancy, as assessed by history, hCG measurement and ultrasonography, management strategies may include expectant management, chemotherapeutic treatment using methotrexate (MTX), or surgical intervention. While these strategies are largely successful, expectant management may result in tubal rupture if the pregnancy does not resolve spontaneously; MTX administration is not always successful and may induce significant side effects; and surgical intervention may result in loss of the already-damaged fallopian tube, further hampering the patient's subsequent attempts to conceive. Nanomaterial-based technologies offer the potential to enhance delivery of diagnostic imaging contrast and therapeutic agents to more effectively and safely manage EP. The purpose of this narrative review is to summarize the current state of nanomedicine technology dedicated to its potential to improve both the diagnosis and treatment of EP.

An miRNA-mRNA integrative analysis in human placentas and mice: role of the Smad2/miR-155-5p axis in the development of fetal growth restriction

Introduction: Functional disorder of the placenta is the principal cause of fetal growth restriction (FGR), usually cured with suitable clinical treatment and good nursing. However, some FGR mothers still give birth to small for gestational age (SGA) babies after treatment. The ineffectiveness of treatment in such a group of patients confused physicians of obstetrics and gynecology. Methods: In this study, we performed a microRNA-messenger RNA integrative analysis of gene expression profiles obtained from Gene Expression Omnibus. Differentially expressed genes were screened and checked using quantitative polymerase chain reaction. Target genes of significantly changed microRNA were screened and enriched for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses. Function of the obtained microRNA-messenger RNA was evaluated using HTR-8/SVneo trophoblast cells, human umbilical vein endothelial cells, and heterozygote male mice. Result: MiR-155-5p was upregulated (p = 0.001, fold-change = 2.275) in fetal-side placentals. Among the hub genes identified as key targets for miR-155-5p in fetal reprogramming, Smad2 was downregulated (p = 0.002, fold change = 0.426) and negatively correlated with miR-155-5p expression levels (r = -0.471, p < 1.0 E - 04) in fetal-side placental tissues. The miR-155-5p mimic blocks Smad2 expression and suppresses villous trophoblast cell and endothelial cell function (proliferation, migration, and invasion), indicating a close relationship with placental development. Luciferase assays further confirmed the targeting of miR-155-5p to Smad2. Furthermore, Smad2^+/- heterozygote male mice were born small with low body weight (p = 0.0281) and fat composition (p = 0.013) in the fourth week post-natal. Discussion: We provide the first evidence of the role of the Smad2/miR-155-5p axis in the placental pathologies of FGR. Our findings elucidate the pathogenesis of FGR and provide new therapeutic targets.

MicroRNA analysis in maternal blood of pregnancies with preterm premature rupture of membranes reveals a distinct expression profile

Objective

To determine the expression profile of microRNAs in the peripheral blood of pregnant women with preterm premature rupture of membranes (PPROM) compared to that of healthy pregnant women.

Study design

This was a pilot study with case-control design in pregnant patients enrolled between January 2017 and June 2019. Patients with healthy pregnancies and those affected by PPROM between 20- and 33+6 weeks of gestation were matched by gestational age and selected for inclusion to the study. Patients were excluded for multiple gestation and presence of a major obstetrical complication such as preeclampsia, diabetes, fetal growth restriction and stillbirth. A total of ten (n = 10) controls and ten (n = 10) patients with PPROM were enrolled in the study. Specimens were obtained before administration of betamethasone or intravenous antibiotics. MicroRNA expression was analyzed for 800 microRNAs in each sample using the NanoString nCounter Expression Assay. Differential expression was calculated after normalization and log2- transformation using the false discovery rate (FDR) method at an alpha level of 5%.

Results

Demographic characteristics were similar between the two groups. Of the 800 miRNAs analyzed, 116 were differentially expressed after normalization. However, only four reached FDR-adjusted statistical significance. Pregnancies affected by PPROM were characterized by upregulation of miR-199a-5p, miR-130a-3p and miR-26a-5p and downregulation of miR-513b-5p (FDR adjusted p-values <0.05). The differentially expressed microRNAs participate in pathways associated with altered collagen and matrix metalloprotease expression in the extracellular matrix.

Conclusion

Patients with PPROM have a distinct peripheral blood microRNA profile compared to healthy pregnancies as measured by the NanoString Expression Assay.

MiR-323a-3p acts as a tumor suppressor by suppressing FMR1 and predicts better esophageal squamous cell carcinoma outcome

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) has unfavorable outcomes with the highest incidence seen in China. Accordingly, exploring effective molecular biomarkers is of great value. MicroRNAs (miRNAs) are posttranscriptional regulators of gene expression and modulate numerous biological processes in tumors. Our study aimed to identify prognostic miRNAs and investigate their role in ESCC.

METHODS

Prognosis-related plasma miRNAs were detected by miRNA microarray and qRT-PCR. Functional assays and molecular mechanism studies were used to investigate the role of miRNA in ESCC.

RESULTS

Over-expression of miR-323a-3p was associated with a favorable prognosis. MiR-323a-3p negatively regulated proliferation, migration, and invasion. Through biological predictions, the fragile X mental retardation 1 (FMR1) was found to be a potential target of miR-323a-3p. Further investigation revealed that miR-323a-3p directly targeted and suppressed FMR1. MiR-323a-3p and FMR1 mRNA, as well as miR-323a-3p and the FMR1-encoded protein FMRP, showed negative correlations. Luciferase activity of FMR1-3'-UTR, but not mutant counterparts, was decreased by mimic compared with that of the control. The compromised cell proliferation, migration, and invasion induced by transfection with miR-323a-3p mimic were rescued by transfection with a FMR1 expression plasmid. Tumors induced by miR-323a-3p overexpressed ESCC cells grew significantly slower in vivo and resulted in smaller tumor masses. Metastatic lung colonization was also inhibited by miR-323a-3p overexpression.

CONCLUSIONS

MiR-323a-3p was significantly associated with survival and acted as a tumor suppressor by inhibiting proliferation, migration, and invasion via the regulation of FMR1. MiR-323a-3p is a promising biomarker and may be a potential therapeutic target.

Effect and Role of miR-196b in Ectopic Pregnancy

Ectopic pregnancy (EP) is associated with significant morbidity and mortality, but the molecular mechanism of this condition is still unclear. miR-196b, a hot research direction for the past few years, participates in the occurrence of various diseases but whether it plays a regulatory role in EP is still unclear. This research was set to investigate the expression and potential value of miR-196b in EP. qRT-PCR was utilized to determine the relative expression of miR-196b in peripheral blood of EP patients and to observe the expression changes of miR-196b before and after treatment. Correlation analysis of miR-196b with HCG and progesterone was performed. Logistic regression analysis was applied to independent risk factors affecting EP patients. TargetScan was utilized to predict the downstream target genes of miR-196b, and GO and KEGG analysis was carried out using the R language pack. qRT-PCR showed that miR-196b expression in peripheral blood of EP patients was lower than that of normal people. miR-196b expression in patients after treatment was notably higher than that before treatment. In addition, correlation analysis showed that miR-196b was positively correlated with the expression of HCG, progesterone, and estradiol. Risk factor analysis revealed that abortion history, pelvic inflammatory disease history, lower abdominal surgery history, and miR-196b were independent risk factors for EP, and the AUC of the combined ROC curve was 0.899. GO function enrichment and KEGG signal pathway enrichment found 10 potential functions and 2 potential signal pathways of miR-196b. miR-196b is expressed in EP patients, is differentially expressed according to the change in EP condition, and is expected to become a promising index for clinical diagnosis of EP.

Serum calponin 2 is a novel biomarker of tubal ectopic pregnancy

OBJECTIVE

To evaluate serum protein calponin 2 (CNN2) as a candidate biomarker for tubal ectopic pregnancy (EP).

DESIGN

Retrospective study.

SETTING

Single University affiliated tertiary hospital.

PATIENT(S)

Serum samples were obtained from 84 patients with EP, 39 with viable intrauterine pregnancy (vIUP), and 42 with miscarriage. Moreover, 10 fallopian tube and corresponding villous tissue samples from patients with EP, 6 villous tissue samples from patients with vIUP, and 10 villous tissue samples from patients with miscarriage were collected.

INTERVENTION(S)

Serum CNN2 concentrations were measured using enzyme-linked immunosorbent assay; CNN2 expression in tissues was evaluated via immunohistochemistry and quantitative real-time polymerase chain reaction analysis.

MAIN OUTCOME MEASURE(S)

The diagnostic performance of serum CNN2 to discriminate an EP from vIUP and miscarriage.

RESULT(S)

CNN2 was highly expressed in villous stromal cells isolated from patients with EP, and CNN2 messenger ribonucleic acid expression was upregulated in villous tissues from women with EP compared with that in women with vIUPs and miscarriages. Serum CNN2 concentration was higher in women with EP than that in women with vIUP and miscarriage. The serum CNN2 predicted EP from vIUP and miscarriage with areas under the curve (AUCs) of 0.931 (95% confidence interval: 0.889-0.975). For discriminating EP from miscarriage only, the AUC was 0.906 (95% confidence interval: 0.835-0.977). In contrast, the AUCs for serum human chorionic gonadotropin were 0.809 and 0.637, respectively.

CONCLUSION(S)

Our data highlight the possibility of serum CNN2 as a single biomarker for the diagnosis of EP.

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR 1900020483.

Aptamer-Based Detection of Circulating Targets for Precision Medicine

The past decade has witnessed ongoing progress in precision medicine to improve human health. As an emerging diagnostic technique, liquid biopsy can provide real-time, comprehensive, dynamic physiological and pathological information in a noninvasive manner, opening a new window for precision medicine. Liquid biopsy depends on the sensitive and reliable detection of circulating targets (e.g., cells, extracellular vesicles, proteins, microRNAs) from body fluids, the performance of which is largely governed by recognition ligands. Aptamers are single-stranded functional oligonucleotides, capable of folding into unique tertiary structures to bind to their targets with superior specificity and affinity. Their mature evolution procedure, facile modification, and affinity regulation, as well as versatile structural design and engineering, make aptamers ideal recognition ligands for liquid biopsy. In this review, we present a broad overview of aptamer-based liquid biopsy techniques for precision medicine. We begin with recent advances in aptamer selection, followed by a summary of state-of-the-art strategies for multivalent aptamer assembly and aptamer interface modification. We will further describe aptamer-based micro-/nanoisolation platforms, aptamer-enabled release methods, and aptamer-assisted signal amplification and detection strategies. Finally, we present our perspectives regarding the opportunities and challenges of aptamer-based liquid biopsy for precision medicine.

Profiling circulating microRNAs in the serum of pregnant and non-pregnant pigs reveals a plethora of reproductive status-dependent microRNAs

Circulating, non-coding RNAs, such as microRNAs (miRNAs) have been proposed to be powerful pathophysiological indicators of pregnancy in animals and humans. Since their discovery, it is known that miRNAs can take part in numerous biological processes, including cell proliferation and differentiation during early embryonic development and establishment of pregnancy. Our recent studies have indicated that maternal blood can carry miRNAs reported previously at the embryo-maternal interface in pigs. To expand the scope of our research, we tested the hypothesis that miRNAs previously identified in conceptuses, trophoblasts, endometrium and uterine lumen-derived extracellular vesicles (EVs) collected before Day 20 of pregnancy can show reproductive status-dependent profiles in the serum of cyclic and pregnant crossbred pigs. Custom-designed TaqMan arrays, multiplex real-time reverse transcription (RT)-PCR and real-time RT-PCR allowed us to identify a number of reproductive status-dependent miRNAs in serum samples collected from pigs during the estrous cycle or pregnancy (Days 16 and 20). We found that serum samples were enriched with miRNAs involved in processes important during the estrous cycle and early pregnancy, e.g. cell sensitivity and viability, angiogenesis, embryonic cell proliferation and differentiation. Further validation revealed different abundance of ssc-miR-143-3p and ssc-miR-125b in pregnant and non-pregnant animals and correlation of ssc-miR-125b levels with litter size. In addition, analyzed serum samples contained both EVs and Argonaute2 proteins, which are known to be involved in miRNA transportation and intercellular communication. In summary, we identified several circulating miRNAs that differ in abundance between cyclic and pregnant animals and could serve as potential indicators of reproductive status in pigs during breeding management.

Circulating serum miR-200c and miR-34a-5p as diagnostic biomarkers for endometriosis

OBJECTIVE

Endometriosis is defined by the presence of endometrial glands and stroma grow in areas outside the uterus. A simple blood test for endometriosis-specific biomarkers would offer a more timely accurate diagnosis of the disease and could lead to earlier treatment intervention. Alterations in microRNA (miRNA) levels in blood may reflect changes during normal physiologic processes and have been related to several pathologic conditions, including gynecologic diseases. In the present study, we aim to evaluate the level of serum miR-34a-5p and miR-200c from women with and without endometriosis, and to explore the potential of miRNAs as reliable non-invasive biomarkers in the diagnosis of endometriosis.

METHODS

Expression levels of miRNAs were performed by quantitative real-time polymerase chain reaction (qRT-PCR). Serum cancer antigen 125 (CA-125) levels were analyzed by autoanalyzer.

RESULTS

miR-34a-5p expression levels were decreased and miR-200c expression levels were increased in the endometriosis patients compared to the control group. According to the areas under the ROC curve (AUC) values, miR-200c and miR-34a-5p may serve as biomarkers for the diagnosis of endometriosis. Serum miR-34a-5p and miR-200c had a sensitivity of 78.95 % and 100 % and a specificity of 49.12 % and 100 %, respectively, for the detection of endometriosis.

CONCLUSION

Serum miRNAs may provide a promising opportunity for diagnosis of endometriosis. Understanding the role of circulating miRNAs will serve a better comprehension of the systemic effects of endometriosis and offer options for new treatments. It is clear that more work is needed in this area.

The role of miRNAs in polycystic ovary syndrome with insulin resistance

PURPOSE

This review aims to summarize the key findings of several miRNAs and their roles in polycystic ovary syndrome with insulin resistance, characterize the disease pathogenesis, and establish a new theoretical basis for diagnosing, treating, and preventing polycystic ovary syndrome.

METHODS

Relevant scientific literature was covered from 1992 to 2020 by searching the PubMed database with search terms: insulin/insulin resistance, polycystic ovary syndrome, microRNAs, and metabolic diseases. References of relevant studies were cross-checked.

RESULTS

The related miRNAs (including differentially expressed miRNAs) and their roles in pathogenesis, and possible therapeutic targets and pathways, are discussed, highlighting controversies and offering thoughts for future directions.

CONCLUSION

We found abundant evidence on the role of differentially expressed miRNAs with its related phenotypes in PCOS. Considering the essential role of insulin resistance in the pathogenesis of PCOS, the alterations of associated miRNAs need more research attention. We speculate that race/ethnicity or PCOS phenotype and differences in methodological differences might lead to inconsistencies in research findings; thus, several miRNA profiles need to be investigated further to qualify for the potential therapeutic targets for PCOS-IR.

A Panel of Plasma miRNAs 199b-3p, 224-5p and Let-7d-3p as Non-Invasive Diagnostic Biomarkers for Endometriosis

The objective of this study was to investigate whether the combination of miR-224-5p, miR-199-3p, and let-7d-3p is a suitable diagnostic panel for endometriosis. Twenty-five women with endometriosis (case) and twenty-five women without any sign of endometriosis (controls) were included. Peripheral blood specimens were collected from all these women who were a proper candidate for laparoscopy before surgery. Total RNA was isolated to synthesize complementary DNA. Expression of miR-199b-3p, miR-224-5p, and let-7d-3p was analyzed by RT-qPCR. To estimate the performance of the identified miRNAs for endometriosis diagnosis, we performed ROC curves analysis. There was an upregulation of miRNAs 199b-3p (P value < 0.001) and down-regulation of 224-5p (P value < 0.001) and miRNA let-7d-3p (P value < 0.05) in women with endometriosis compared to non-endometriosis women. The diagnostic accuracy of miRNAs 199b-3p, 224-5p, and let-7d-3p was measured by AUC which was 0.843 (sensitivity = 96% and specificity = 80%), 0.914 (sensitivity = 84% and specificity = 80%), and 0.696 (sensitivity = 80% and specificity = 56%) for miRNAs 199b-3p, 224-5p, and let-7d-3p, respectively. In combination, they showed the highest accuracy with the AUC 0.992 (sensitivity = 96% and specificity = 100%). In conclusion(s) the levels of miRNAs 199b-3p, 224-5p, and Let-7d-3p in plasma are potential diagnostic biomarkers for endometriosis patients.

Using dynein heavy chain 5 and creatine kinase levels in cervical fluid and blood for early diagnosing of ectopic pregnancy

AIM

Ectopic pregnancy is a life-threatening problem in reproductive ages. Diagnosing ectopic pregnancy in the early period provides to reducing mortality and morbidity and gives an opportunity for medical treatment to preserve fallopian tubes. Evaluation of cervical fluid for determining ectopic pregnancy with new promising markers provided different aspects for diagnosing ectopic pregnancy in the present study.

METHODS

In this prospective clinical study, ectopic pregnant patients as ectopic pregnancy group (n = 46), intrauterine pregnant patients as intrauterine pregnancy group (n = 29) and not-pregnant patients as nonpregnancy group (n = 10) participated to study. Cervical fluid samples were collected with using merocel sponge. In addition, serum samples were obtained from patients. Dynein heavy chain 5 (DNAH5) and creatine kinase (CK) levels were determined by enzyme-linked immunosorbent assay kits in samples.

RESULTS

Reduced cervical fluid DNAH5 levels was diagnosed in ectopic pregnancy group compared to intrauterine pregnancy group (median 3.42 ng/mL; 25-75% percentile 0-9.56 ng/mL vs median 6.14 ng/mL; 1.40-8.31 ng/mL; P < 0.001). On the other hand, DNAH5 protein was not detected in nonpregnant patients' samples. In addition, statistical significant increased cervical fluid CK levels were diagnosed in ectopic pregnancy group compared to intrauterine pregnancy group (median 4477.61 IU/L; 0-64 925.37 IU/L vs 0 IU/L; 0-6832.30 IU/L; P = 0.006).

CONCLUSION

Measuring of CK and DNAH5 in cervical fluid could be promising markers for early diagnosing of ectopic pregnancy. Decreased DNAH5 levels in cervical fluid might be result from abnormal cilia function in ectopic pregnant patients. ClinicalTrials.gov ID. NCT02995356.

Maternal plasma miRNAs as potential biomarkers for detecting risk of small-for-gestational-age births

Background

Small-for-gestational-age fetuses (SGA) (birthweight <10th centile) are at high risk for stillbirth or long-term adverse outcomes. Here, we investigate the ability of circulating maternal plasma miRNAs to determine the risk of SGA births.

Methods

Maternal plasma samples from 29 women of whom 16 subsequently delivered normally grown babies and 13 delivered SGA (birthweight <5th centile) were selected from a total of 511 women recruited to form a discovery cohort in which expression data for a total of 800 miRNAs was determined using the Nanostring nCounter miRNA assay. Validation by RT-qPCR was performed in an independent cohort.

Findings

Partial least-squares discriminant analysis (PLS-DA) of the Nanostring nCounter miRNA assay initially identified seven miRNAs at 12–14⁺⁶ weeks gestation, which discriminated between SGA cases and controls. Four of these were technically validated by RT-qPCR. Differential expression of two miRNA markers; hsa-miR-374a-5p (p = 0•0176) and hsa-let-7d-5p (p = 0•0036), were validated in an independent population of 95 women (SGA n = 12, Control n = 83). In the validation cohort, which was enriched for SGA cases, the ROC AUCs were 0•71 for hsa-miR-374a-5p, and 0•74 for hsa-let-7d-5p, and 0•77 for the two combined.

Interpretation

Whilst larger population-wide studies are required to validate their performance, these findings highlight the potential of circulating miRNAs to act as biomarkers for early prediction of SGA births.

Funding

This work was supported by Genesis Research Trust, March of Dimes, and the National Institute for Health Research Biomedical Research Centre (NIHR BRC) based at Imperial Healthcare NHS Trust and Imperial College London.

A role for microRNAs in the epigenetic control of sexually dimorphic gene expression in the human placenta

Aim: The contribution of miRNAs as epigenetic regulators of sexually dimorphic gene expression in the placenta is unknown. Materials & methods: 382 placentas from the extremely low gestational age newborns (ELGAN) cohort were evaluated for expression levels of 37,268 mRNAs and 2,102 miRNAs using genome-wide RNA-sequencing. Differential expression analysis was used to identify differences in the expression based on the sex of the fetus. Results: Sexually dimorphic expression was observed for 128 mRNAs and 59 miRNAs. A set of 25 miRNA master regulators was identified that likely contribute to the sexual dimorphic mRNA expression. Conclusion: These data highlight sex-dependent miRNA and mRNA patterning in the placenta and provide insight into a potential mechanism for observed sex differences in outcomes.

MiR-519d-3p in Trophoblastic Cells: Effects, Targets and Transfer to Allogeneic Immune Cells via Extracellular Vesicles

Members of the placenta-specific miRNA cluster C19MC, including miR-519d, are secreted by fetal trophoblast cells within extracellular vesicles (EVs). Trophoblast-derived EVs can be internalized by the autologous trophoblast and surrounding maternal immune cells, resulting in coordination of cellular responses. The study of functions and targets of placental miRNAs in the donor and recipient cells may contribute to the understanding of the immune tolerance essential in pregnancy. Here, we report that miR-519d-3p levels correlate positively with cell proliferation and negatively with migration in trophoblastic cell lines. Inhibition of miR-519d-3p in JEG-3 cells increases caspase-3 activation and apoptosis. PDCD4 and PTEN are targeted by miR-519d-3p in a cell type-specific manner. Transfection of trophoblastic cell lines with miR-519d mimic results in secretion of EVs containing elevated levels of this miRNA (EV_miR-519d). Autologous cells enhance their proliferation and decrease their migration ability when treated with EV_miR-519d. NK92 cells incorporate EV-delivered miR-519d-3p at higher levels than Jurkat T cells. EV_miR-519d increases the proliferation of Jurkat T cells but decreases that of NK92 cells. Altogether, miR-519d-3p regulates pivotal trophoblast cell functions, can be transferred horizontally via EVs to maternal immune cells and exerts functions therein. Vesicular miRNA transfer from fetal trophoblasts to maternal immune cells may contribute to the immune tolerance in pregnancy.

Endometrial microRNAs and their aberrant expression patterns

MicroRNAs (miRNAs) are a class of small noncoding RNAs that regulate gene expression. They play fundamental roles in several biological processes, including cell differentiation and proliferation, embryo development, organ development, and organ metabolism. Besides regulating the physiological processes, miRNAs regulate various pathological conditions such as tumors, metastases, metabolic diseases, and osteoporosis. Although several studies have been performed on miRNAs, only few studies have described the miRNA expression and functions in human reproductive tract tissues. During menstruation, the human endometrium undergoes extensive cyclic morphological and biochemical modifications before embryo implantation. In addition to the ovarian steroid hormones (estrogen and progesterone), endometrial autocrine or paracrine factors and embryo-derived signals play a significant role in endometrial functions. miRNAs are considered key regulators of gene expression in the human endometrium and implantation process, and their aberrant expression levels are associated with the development of various disorders, including tumorigenesis. In this review, we summarize the studies that show the role of miRNAs in regulating the physiological conditions of the endometrium and the implantation process and discuss the aberrant expression of miRNAs in ectopic pregnancy, endometriosis, and endometrial cancer.

The role of microRNAs in ectopic pregnancy: A concise review

Ectopic pregnancy (EP) is reported in about 1%–2% of pregnant females and is associated with mortality and morbidity. Several genetic and environmental factors might modulate occurrence of EP. Prediction of EP and patients' follow-up is an important task in management of pregnancy. MicroRNAs (miRNAs) as non-coding RNAs with sizes between 21 and 24 nucleotides have been shown to regulate several aspects of implantation and early fetal life. They have potential role in early detection of EP especially considering their presence in body fluids such as serum. Assessment of their expression in serum might provide a noninvasive method for diagnosis and patients' follow-up. However, data regarding their role in EP is not sufficient due to small sample sizes of the studies. Future studies are required to find miRNAs that regulate expression of EP-associated genes such as VEGFA, EGFR, ESR1 and immune response-related genes to provide new diagnostic biomarkers for EP.

Circulating microRNA 134 sheds light on the diagnosis of major depressive disorder

Major depressive disorder (MDD) is a prevalent and debilitating psychiatric mood disorder that lacks objective laboratory-based tests to support its diagnosis. A class of microRNAs (miRNAs) has been found to be centrally involved in regulating many molecular processes fundamental to central nervous system function. Among these miRNAs, miRNA-134 (miR-134) has been reported to be related to neurogenesis and synaptic plasticity. In this study, the hypothesis that plasma miR-134 can be used to diagnose MDD was tested. Perturbation of peripheral and central miR-134 in a depressive-like rat model was also examined. By reverse-transcription quantitative PCR, miR-134 was comparatively measured in a small set of plasma samples from MDD and healthy control (HC) subjects. To determine its diagnostic efficacy, plasma miR-134 levels were assessed in 100 MDD, 50 bipolar disorder (BD), 50 schizophrenic (SCZ), and 100 HC subjects. A chronic unpredictable mild stress (CUMS) rat model was also developed to evaluate miR-134 expression in plasma, hippocampus (HIP), prefrontal cortex (PFC), and olfactory bulb. We found that plasma miR-134 was significantly downregulated in MDD subjects. Diagnostically, plasma miR-134 levels could effectively distinguish MDD from HC with 79% sensitivity and 84% specificity, while distinguishing MDD from HC, BD, and SCZ subjects with 79% sensitivity and 76.5% specificity. Congruent with these clinical findings, CUMS significantly reduced miR-134 levels in the rat plasma, HIP, and PFC. Although limited by the relatively small sample size, these results demonstrated that plasma miR-134 displays potential ability as a biomarker for MDD.

Extracellular Vesicles Mediated Early Embryo-Maternal Interactions

Embryo-maternal crosstalk is an important event that involves many biological processes, which must occur perfectly for pregnancy success. This complex communication starts from the zygote stage within the oviduct and continues in the uterus up to the end of pregnancy. Small extracellular vesicles (EVs) are part of this communication and carry bioactive molecules such as proteins, lipids, mRNA, and miRNA. Small EVs are present in the oviductal and uterine fluid and have important functions during fertilization and early embryonic development. Embryonic cells are able to uptake oviductal and endometrium-derived small EVs. Conversely, embryo-derived EVs might modulate oviductal and uterine function. In this review, our aim is to demonstrate the role of extracellular vesicles modulating embryo-maternal interactions during early pregnancy.

Mesenchymal stem cells derived exosomal miR-323-3p promotes proliferation and inhibits apoptosis of cumulus cells in polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is a heterogeneous reproductive disease. Adipose mesenchymal stem cells (AMSCs) can produce a mass of exosomes. The objective of this study was to determine the effects of exosomal miR-323-3p on cumulus cells (CCs) of PCOS patients. Exosomal miR-323-3p were collected from modified AMSCs. Real-time PCR, western blots, MTT assays, flow cytometry, luciferase reporter assays and a letrozole-induced PCOS mouse model were used to identify mechanisms of exosomal miR-323-3p on CCs. The results revealed that miR-323-3p expression was upregulated in AMSCs, exosomes and CCs. Upregulated miR-323-3p promoted cell proliferation and suppressed apoptosis in CCs, while miR-323-3p inhibitor exerted opposite roles in exosome-treated CCs. Moreover, PDCD4 was upregulated in PCOS CCs, displayed an inverse expression pattern to those of miR-323-3p, and was a direct target of miR-323-3p. Overexpression of PDCD4 reversed the effects of upregulated miR-323-3p on CCs. Serum FSH, LH and testosterone were upregulated while E2 levels were downregulated in the PCOS mice. Upregulation of miR-323-3p alleviated PCOS by suppressing CCs' apoptosis through targeting PDCD4 in vivo. The results demonstrated that exosomal miR-323-3p promoted cell proliferation and inhibited apoptosis in CCs through targeting PDCD4 in PCOS. This study provides insight into developing new therapeutic strategies for PCOS.

Identification of microRNA signatures in umbilical cord blood associated with maternal characteristics

Background

Umbilical cord blood could serve as useful source of blood markers enabling more efficient and reliable prenatal and neonatal diagnostics. MicroRNAs (miRNAs) are ubiquitous in body fluids where they were used for detecting and monitoring various physiological and pathological conditions. In this descriptive study, we aimed to identify changes in miRNA expression profiles associated with basic maternal somatic and epidemiological characteristics.

Methods

Study is based on 24 mothers from the Pilot phase of CELSPAC: TNG (Central European Longitudinal Studies of Parents and Children: The Next Generation) study. Cord blood was collected at time of delivery and global miRNA profiling was performed using microRNA Ready-to-use PCR Human Panel I+II TaqMan microarrays. Expression profiles were statistically evaluated in relation to maternal age, BMI, pregnancy weight gain, blood type, Rh factor status, allergies during pregnancy, addictive substance abuse and smoking status.

Results

We analyzed expression of 752 human mature miRNAs in 24 samples of umbilical cord blood. For all maternal characteristics tested we described a specific signature of significantly deregulated miRNAs (P < 0.05). Analysis revealed seven miRNA associated with maternal age (three increased and four decreased in women younger than 35 years), 14 miRNAs associated with BMI status (five miRNAs increased and nine miRNAs decreased in women with BMI > 25) and nine miRNAs associated with maternal weight gain during pregnancy (eight miRNAs increased, and one miRNA decreased in women with weight gain < 12 kg). Additionally, 17 miRNAs correlated to blood type (two miRNAs decreased in blood type A, 11 increased in blood type B, two miRNAs increased in blood type AB and two miRNAs increased in blood type 0) and 17 miRNAs to Rh status of mother. We also detected seven miRNAs deregulated in umbilical cord blood of women with allergy (four increased and three decreased in women with allergy), four miRNAs associated to addictive substance abuse status (two up- and two downregulated in women with addictive substance abuse) and eight miRNAs associated with maternal cigarette smoking during pregnancy.

Conclusions

We successfully described differences in miRNA profiles in umbilical cord blood associated with basic characteristics connected with mother. Our data suggest that miRNAs in umbilical cord blood are detectable and associated with a wide range of maternal characteristics. These results indicate that miRNAs could potentially serve, and should be studied, as biomarkers for screening and diagnosis of pregnancy-associated complications and pathologies.

Deregulation of miR-324/KISS1/kisspeptin in early ectopic pregnancy: mechanistic findings with clinical and diagnostic implications

BACKGROUND

Ectopic pregnancy is a life-threatening condition for which novel screening tools that would enable early accurate diagnosis would improve clinical outcomes. Kisspeptins, encoded by KISS1, play an essential role in human reproduction, at least partially by regulating placental function and possibly embryo implantation. Kisspeptin levels are elevated massively in normal pregnancy and reportedly altered in various gestational pathologic diseases. Yet, the pathophysiologic role of KISS1/kisspeptin in ectopic pregnancy has not been investigated previously.

OBJECTIVE

The purpose of this study was to evaluate changes of KISS1/kisspeptin levels in ectopic pregnancy and their underlaying molecular mechanisms and to ascertain the diagnostic implications of these changes.

STUDY DESIGN

A total of 122 women with normal pregnancy who underwent voluntary termination of pregnancy and 84 patients who experienced tubal ectopic pregnancy were recruited. Measurements of plasma kisspeptins and KISS1 expression analyses in human embryonic/placental tissue were conducted in ectopic pregnancy and voluntary termination of pregnancy control subjects during the early gestational window (<12 weeks). Putative microRNA regulators of KISS1 were predicted in silico, followed by expression analyses of selected microRNAs and validation of repressive interactions in vitro. Circulating levels of these microRNAs were also assayed in ectopic pregnancy vs voluntary termination of pregnancy.

RESULTS

Circulating kisspeptins gradually increased during the first trimester of normal pregnancy but were reduced markedly in ectopic pregnancy. This profile correlated with the expression levels of KISS1 in human embryonic/placental tissue, which increased in voluntary termination of pregnancy but remained suppressed in ectopic pregnancy. Bioinformatic predictions and expression analyses identified miR-27b-3p and miR-324-3p as putative repressors of KISS1 in human embryonic/placental tissue at <12 weeks gestation, when expression of microRNAs was low in voluntary termination of pregnancy control subjects but significantly increased in ectopic pregnancy. Yet, a significant repressive interaction was documented only for miR-324-3p, occurring at the predicted 3'-UTR of KISS1. Interestingly, circulating levels of miR-324-3p, but not of miR-27b-3p, were suppressed distinctly in ectopic pregnancy, despite elevated tissue expression of the pre-microRNA. A decision-tree model that used kisspeptin and miR-324-3p levels was successful in discriminating ectopic pregnancy vs voluntary termination of pregnancy, with a receiver-operating characteristic area under the curve of 0.95±0.02 (95% confidence interval).

CONCLUSION

Our results document a significant down-regulation of KISS1/kisspeptins in early stages of ectopic pregnancy via, at least partially, a repressive interaction with miR-324-3p. Our data identify circulating kisspeptins and miR-324-3p as putative biomarkers for accurate screening of ectopic pregnancy at early gestational ages.

RNA-sequencing analysis of umbilical cord plasma microRNAs from healthy newborns

MicroRNAs are a class of small non-coding RNA that regulate gene expression at a post-transcriptional level. MicroRNAs have been identified in various body fluids under normal conditions and their stability as well as their dysregulation in disease has led to ongoing interest in their diagnostic and prognostic potential. Circulating microRNAs may be valuable predictors of early-life complications such as birth asphyxia or neonatal seizures but there are relatively few data on microRNA content in plasma from healthy babies. Here we performed small RNA-sequencing analysis of plasma processed from umbilical cord blood in a set of healthy newborns. MicroRNA levels in umbilical cord plasma of four male and four female healthy babies, from two different centres were profiled. A total of 1,004 individual microRNAs were identified, which ranged from 426 to 659 per sample, of which 269 microRNAs were common to all eight samples. Many of these microRNAs are highly expressed and consistent with previous studies using other high throughput platforms. While overall microRNA expression did not differ between male and female cord blood plasma, we did detect differentially edited microRNAs in female plasma compared to male. Of note, and consistent with other studies of this type, adenylation and uridylation were the two most prominent forms of editing. Six microRNAs, miR-128-3p, miR-29a-3p, miR-9-5p, miR-218-5p, 204-5p and miR-132-3p were consistently both uridylated and adenylated in female cord blood plasma. These results provide a benchmark for microRNA profiling and biomarker discovery using umbilical cord plasma and can be used as comparative data for future biomarker profiles from complicated births or those with early-life developmental disorders.

miR-323-3p regulates the steroidogenesis and cell apoptosis in polycystic ovary syndrome (PCOS) by targeting IGF-1

Polycystic ovary syndrome (PCOS) is an endocrine and metabolic heterogeneous disorder. The incidence of which reaches 5% to 10% among reproductive-age women. Abnormal folliculogenesis is considered to be a common characteristic of PCOS, but the cause of this disorder and its pathogenesis still remain uncertain. Previous studies had proved that dysregulation of microRNAs is related to the pathogenesis of PCOS. In this study, we investigated the effect of miR-323-3p on the human cumulus cells (CCs). We also investigated the underlying mechanisms of miR-323-3p on human granulosa-like tumor cell line (KGN) or primary human CCs by stimulating with Dihydrotestosterone (DHT). Our findings suggested that the level of miR-323-3p in human CCs of women with PCOS was down-regulated, compared with that of the control group. Moreover, the inhibition of the level of miR-323-3p could up-regulate of the steroidogenesis and promote the apoptosis in KGN cells. In addition, our data confirmed that the Insulin-like growth factor 1 (IGF-1) gene was the direct target of miR-323-3p. Furthermore, the mimic of miR-323-3p inhibited the expression of IGF-1, which down-regulated the levels of AR, AMHR-II, CYP19A, EGFR, and GATA-4. In conclusion, miR-323-3p targeting IGF-1 regulates the steroidogenesis and the activity of CCs, which plays an important role in the occurrence and development of PCOS. Our results have shown that miR-323-3p is a novel and promising molecular target for the improvement of the dysfunction of CCs in PCOS.

hsa-miRNA-154-5p expression in plasma of endometriosis patients is a potential diagnostic marker for the disease

RESEARCH QUESTION

As microRNA (miRNA) are stable in circulation, this study tested whether they could serve as putative non-invasive biomarkers for endometriosis, and their expression differences between endometriosis patients and controls. It also addressed whether the combination of differently expressed miRNA together with clinical parameters in a statistical model could distinguish between endometriosis patients and controls.

DESIGN

This prospective cohort study explored the possibility of using changes in extracellular miRNA spectra in plasma of 51 patients with endometriosis compared with 41 controls combined with clinical data as non-invasive biomarkers for the disease. The project was divided into three different phases for biomarker screening, discovery and validation. The differences in expression levels of plasma miRNA obtained from women with and without endometriosis were analysed with quantitative PCR-based microarrays. The diagnostic performance of the selected individual and/or combined differentially expressed miRNA candidates and clinical parameters was assessed using in silico bioinformatics modelling and receiver operating characteristic curve analysis.

RESULTS

Data showed that a specific plasma miRNA signature is associated with endometriosis and that hsa-miR-154-5p, which alone or in combination with hsa-miR-196b-5p, hsa-miR-378a-3p, and hsa-miR-33a-5p and the clinical parameters of body mass index and age, are potentially applicable for non-invasive diagnosis of the disease. Changes in the levels of expression of certain circulating plasma miRNA also occurred within the phases of the menstrual cycle.

CONCLUSIONS

miRNA seem to be promising candidates for the non-invasive diagnosis of endometriosis. Further, other clinical parameters may help in distinguishing women suffering from endometriosis from healthy individuals.

MicroRNAs as Potential Serum Biomarkers for Early Detection of Ectopic Pregnancy

Diagnosis of ectopic pregnancy relies on both ultrasound findings and human chorionic gonadotropin (hCG) measurements but due to the need for serial tests, tubal rupture and death represent major maternal and fetal risks. Early detection of ectopic pregnancy is essential and thus a noninvasive diagnostic tool seems crucial for the prevention of adverse effects since studies suggest there is a specific relationship between ectopic pregnancy and increasing microRNA factors. Human fluids in women with ectopic pregnancy reveal a particular change in comparison to healthy women. In addition to certain placental microRNAs circulating through plasma that present a specific concentration and serum profile, microRNAs seem to be possible biomarkers for the detection of pregnancy complications linked to placental pathologies. The aim of this study is to review current literature considering the expression levels of several circulating microRNAs that have shown to be novel potential biomarkers for the diagnosis of tubal ectopic pregnancy.

Extracellular vesicle RNAs reflect placenta dysfunction and are a biomarker source for preterm labour

Preterm birth (PTB) can lead to lifelong complications and challenges. Identifying and monitoring molecular signals in easily accessible biological samples that can diagnose or predict the risk of preterm labour (PTL) in pregnant women will reduce or prevent PTBs. A number of studies identified putative biomarkers for PTL including protein, miRNA and hormones from various body fluids. However, biomarkers identified from these studies usually lack consistency and reproducibility. Extracellular vesicles (EVs) in circulation have gained significant interest in recent years as these vesicles may be involved in cell‐cell communication. We have used an improved small RNA library construction protocol and a newly developed size exclusion chromatography (SEC)‐based EV purification method to gain a comprehensive view of circulating RNA in plasma and its distribution by analysing RNAs in whole plasma and EV‐associated and EV‐depleted plasma. We identified a number of miRNAs in EVs that can be used as biomarkers for PTL, and these miRNAs may reflect the pathological changes of the placenta during the development of PTL. To our knowledge, this is the first study to report a comprehensive picture of circulating RNA, including RNA in whole plasma, EV and EV‐depleted plasma, in PTL and reveal the usefulness of EV‐associated RNAs in disease diagnosis.

MicroRNA co-expression networks exhibit increased complexity in pancreatic ductal compared to Vater's papilla adenocarcinoma

MiRNA expression abnormalities in adenocarcinoma arising from pancreatic ductal system (PDAC) and Vater's papilla (PVAC) could be associated with distinctive pathologic features and clinical cancer behaviours. Our previous miRNA expression profiling data on PDAC (n=9) and PVAC (n=4) were revaluated to define differences/similarities in miRNA expression patterns. Afterwards, in order to uncover target genes and core signalling pathways regulated by specific miRNAs in these two tumour entities, miRNA interaction networks were wired for each tumour entity, and experimentally validated target genes underwent pathways enrichment analysis. One hundred and one miRNAs were altered, mainly over-expressed, in PDAC samples. Twenty-six miRNAs were deregulated in PVAC samples, where more miRNAs were down-expressed in tumours compared to normal tissues. Four miRNAs were significantly altered in both subgroups of patients, while 27 miRNAs were differentially expressed between PDAC and PVAC. Although miRNA interaction networks were more complex and dense in PDAC than in PVAC, pathways enrichment analysis uncovered a functional overlapping between PDAC and PVAC. However, shared signalling events were influenced by different miRNA and/or genes in the two tumour entities. Overall, specific miRNA expression patterns were involved in the regulation of a limited core signalling pathways in the biology landscape of PDAC and PVAC.

Role of microRNAs in embryo implantation

Failure of embryo implantation is a major limiting factor in early pregnancy and assisted reproduction. Determinants of implantation include the embryo viability, the endometrial receptivity, and embryo-maternal interactions. Multiple molecules are involved in the regulation of implantation, but their specific regulatory mechanisms remain unclear. MicroRNA (miRNA), functioning as the transcriptional regulator of gene expression, has been widely reported to be involved in embryo implantation. Recent studies reveal that miRNAs not only act inside the cells, but also can be released by cells into the extracellular environment through multiple packaging forms, facilitating intercellular communication and providing indicative information associated with physiological and pathological conditions. The discovery of extracellular miRNAs shed new light on implantation studies. MiRNAs provide new mechanisms for embryo-maternal communication. Moreover, they may serve as non-invasive biomarkers for embryo selection and assessment of endometrial receptivity in assisted reproduction, which improves the accuracy of evaluation while reducing the mechanical damage to the tissue. In this review, we discuss the involvement of miRNAs in embryo implantation from several aspects, focusing on the role of extracellular miRNAs and their potential applications in assisted reproductive technologies (ART) to promote fertility efficiency.

Potential role of microRNAs in mammalian female fertility

Since the first evidence for the involvement of microRNAs (miRNAs) in various reproductive processes through conditional knockout of DICER, several studies have been conducted to investigate the expression pattern and role of miRNAs in ovarian follicular development, oocyte maturation, embryo development, embryo-maternal communication, pregnancy establishment and various reproductive diseases. Although advances in sequencing technology have fuelled miRNA studies in mammalian species, the presence of extracellular miRNAs in various biological fluids, including follicular fluid, blood plasma, urine and milk among others, has opened a new door in miRNA research for their use as diagnostic markers. This review presents data related to the identification and expression analysis of cellular miRNA in mammalian female fertility associated with ovarian folliculogenesis, oocyte maturation, preimplantation embryo development and embryo implantation. In addition, the relevance of miRNAs to female reproductive disorders, including polycystic ovary syndrome (PCOS), endometritis and abnormal pregnancies, is discussed for various mammalian species. Most importantly, the mechanism of release and the role of extracellular miRNAs in cell-cell communication and their potential role as non-invasive markers in female fertility are discussed in detail. Understanding this layer of regulation in female reproduction processes will pave the way to understanding the genetic regulation of female fertility in mammalian species.

Differential miR-346 and miR-582-3p Expression in Association with Selected Maternal and Fetal Complications

Several miRNAs are expressed in human gestational tissue, and some have been shown to be associated with placental dysfunction and complicated pregnancy outcomes. To investigate the roles of miR-346 and miR-582-3p in adverse obstetric events, we analyzed these 2 miRNAs in three samples (maternal blood, umbilical cord blood and placenta) obtained from pregnant women in four groups, including healthy control (n = 60), preeclampsia (n = 31), preterm delivery (n = 29) and small for gestational age (n = 19) patients. The expression levels of miR-346 and miR-582-3p in all included adverse obstetric outcome groups were significantly higher in the maternal plasma samples but lower in the placenta samples (all p value < 0.05). In addition, the miR-346 expression levels in fetal cord blood were also significantly lower in all of the included adverse obstetric outcome groups (all p < 0.05). Multivariate analysis of the three specimens after adjusting for maternal age and gestational age at delivery gave the same results. In conclusion, aberrant miR-346 and miR-582-3p expression level in pregnancy was associated with multiple maternal and fetal complications. Their differential expression in maternal blood, umbilical cord blood and placenta could be potential biomarkers or therapeutic targets for adverse obstetric outcomes

Signs of embryo-maternal communication: miRNAs in the maternal serum of pregnant pigs

Circulating miRNAs were proposed to be indicators of normal or complicated pregnancies. Based on this knowledge and our recent transcriptomic approach showing expression of miRNAs in the porcine endometrium, conceptuses and uterine extracellular vesicles during pregnancy, we have hypothesized that signs of ongoing local embryo-maternal crosstalk involving miRNAs can be detected in the circulation of pregnant gilts as early as a few days after maternal recognition of pregnancy. By applying several molecular biology techniques that differ in dynamic range and precision in maternal serum of Day 16 pregnant pigs, we were able to show for the first time increased levels of several miRNAs, previously reported to be expressed in either conceptuses and extracellular vesicles (miR-26a and miR-125b) or pregnant endometrium (miR-23b). Our results clearly showed that real-time RT-PCR and digital PCR are the most reliable methods, being able to detect small-fold changes of low-abundant circulating miRNAs. Further validation in a separate group of gilts confirmed an increase in miR-23b and miR-125b levels. In silico analyses identified pregnancy-related biological processes and pathways affected by these miRNAs. Target prediction analysis revealed hundreds of porcine transcripts with conserved sites for these miRNAs, which were classified into signaling pathways relevant to pregnancy. We conclude that a unique set of miRNAs can already be observed in the circulation of pigs during the first weeks of pregnancy, as a result of the initiation of embryo-maternal communication.

miR-346 and miR-582-3p-regulated EG-VEGF expression and trophoblast invasion via matrix metalloproteinases 2 and 9

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) is an important regulator for embryo implantation and placental development, and is clinically associated with several obstetric disorders related to insufficient or inappropriate trophoblast invasion, such as recurrent abortion, preeclampsia, and intrauterine fetal growth restriction. This study was performed to identify the microRNAs targeting EG-VEGF, and evaluate the regulatory effect on trophoblast biology. miR-346 and miR-582-3p were initially identified via bioinformatic tools, and their specific binding sites on the EG-VEGF 3'UTR were further confirmed using dual luciferase and a co-transfection assays. miR-346 and miR-582-3p were demonstrated not only to suppress EG-VEGF expression, but also inhibit trophoblast invasion and migration in the JAR and HTR-8/SVneo cell lines. We further evaluated the effect of microRNAs in HTR-8/SVneo cells coexpressing EG-VEGF and miR-346 or miR-582-3p on matrix metalloproteinase (MMP 2 and MMP 9) and the tissue inhibitors of metalloproteinase (TIMP 1 and TIMP 2) using RT-PCR, western blotting and gelatin zymography. TIMP 1 and TIMP 2 were not affected by the two microRNAs, whereas the expressions and activities of MMP 2 and MMP 9 were significantly downregulated, which in turn inhibited the invasion ability of trophoblasts. In conclusion, miR-346 and miR-582-3p regulate EG-VEGF-induced trophoblast invasion through repressing MMP 2 and MMP 9, and may become novel diagnostic biomarkers or therapeutic targets for EG-VEGF-related obstetric disorders. © 2016 BioFactors, 43(2):210-219, 2017.

MicroRNAs: Biomarkers, Diagnostics, and Therapeutics

MicroRNAs (miRNAs) are small noncoding RNAs (21-23 nucleotides in length) that regulate gene expression at translational or posttranslational levels. The major regulatory mechanisms include translational repression or mRNA degradation (Filipowicz et al., Curr Opin Struct Biol 15:331-341, 2005).Aberrant expression of miRNAs has been found to be associated with a variety of human diseases such as cancers/tumors, diabetes, viral infections, cardiovascular diseases, neurodegenerative diseases, and other diseases (Wang et al., J Cell Physiol 23:25-30, 2016; Lawrie, MicroRNAs in medicine, 2013). The expression of miRNAs is tissue specific and can be used to identify tumor type and its origin (Mishra and Merlino, J Clin Invest 119:2119-2123, 2009). Many investigations suggest that the miRNA-expression profiles are novel diagnostic and prognostic biomarkers for multiple human diseases. Manipulating relevant miRNA expression or function may serve as potential therapeutic strategies for different diseases.

Endogenous and exogenous miR-520c-3p modulates CD44-mediated extravillous trophoblast invasion

INTRODUCTION

Adequate extravillous trophoblast (EVT) invasion is essential for successful placentation. Although miR-520c-3p plays an important role in CD44-mediated invasion in cancer cells, there is little information on whether miR-520c-3p is involved in the regulatory mechanisms of CD44-mediated EVT invasion.

METHODS

We screened first trimester trophoblast cells and trophoblast cell lines for expression of miR-520c-3p using real-time polymerase chain reaction. The cell invasion assay was performed using EVT cell lines, HTR8/SVneo and HChEpC1b, to investigate the capability of suppressing EVT invasion by miR-520c-3p. Laser microdissection analysis was then used to determine whether miR-520c-3p was present in the first trimester decidua. Finally, the possibility of chorionic villous trophoblast (CVT)-EVT communication via exosomal miR-520c-3p was determined using an in vitro model based on BeWo exosomes and the EVT cell lines as recipient cells.

RESULTS

The miR-520c-3p level was significantly downregulated in EVT cell lines and EVTs. Cell invasion was significantly inhibited in miR-520c-3p-overexpressing cell lines, involving a significant reduction of CD44. Laser microdissection analysis showed that miR-520c-3p in the periarterial area of the decidua was significantly higher than that in the non-periarterial area. Using an in vitro model system, BeWo exosomal miR-520c-3p was internalized into the EVT cells with subsequently reduced cell invasion via CD44 repression.

CONCLUSIONS

EVT invasion is synergistically enhanced by the reciprocal expression of endogenous miR-520c-3p and CD44. The present study supports a novel model involving a placenta-associated miRNA function in cell-cell communication in which CVT exosomal miR-520c-3p regulates cell invasion by targeting CD44 in EVTs.

Circulating Levels of Pregnancy-Associated, Placenta-Specific microRNAs in Pregnant Women With Placental Abruption

The aim of this study was to clarify the association between circulating pregnancy-associated, placenta-specific microRNAs (miRNAs) in maternal plasma and placental abruption. All samples were obtained after receiving written informed consent, and the study protocol was approved by the institutional review board. Maternal blood samples (7 mL) were obtained at 25 to 40 weeks of gestation from 15 cases of placental abruption (placental abruption group) and from 24 cases of uncomplicated pregnancies (uncomplicated pregnancy group). The plasma concentrations of pregnancy-associated, placenta-specific miRNAs (miR-515-3p, -517a, -517c, and -518b) were measured by quantitative real-time reverse transcription-polymerase chain reaction. There were no significant differences in clinical characteristics between the 2 groups. The median concentration of plasma cell-free miR-517c in the placental abruption group was 21 672.2 copies/mL, whereas that in the uncomplicated pregnancy group was 13 452.0 copies/mL (Mann-Whitney U test, P = .047). Receiver operating characteristic curve analysis revealed that plasma cell-free miR-517c levels discriminated placental abruption from uncomplicated pregnancy with an area under the curve of 0.692. When a cutoff negative/positive value of 15 669.6 copies/mL was selected, the sensitivity and specificity were 73.3% and 62.5%, respectively. In addition, the positive and negative predictive values were 55.0% and 78.9%, respectively. Plasma cell-free miR-517a and miR-517c levels in the large abruption (degree of abruption ≥50% of placenta) group were significantly higher than in the small abruption (<50%) group ( P = .03 for both miRNAs). In conclusion, the circulating level of cell-free miR-517c in maternal plasma was increased as a consequence of placental abruption and may be a potential biomedical marker for placental abruption.

MicroRNAs in acute pancreatitis

Acute pancreatitis is an acute inflammatory condition of the pancreas that can develop into a complicated clinical course with severe local and systemic complications, resulting in a prolonged clinical course with considerable mortality. MicroRNAs (miRNAs), a class of small non-coding RNA molecules that negatively regulate gene expression, have potential value in clinical research and biomarker discovery. In recent years, accumulating evidence suggests that miRNAs may act as potential biomarkers for pancreatic tissue injury, and much attention has been paid to those miRNAs involved in acute pancreatitis. However, the role of miRNAs in acute pancreatitis has been validated in very few clinical studies. A better understanding of the role that miRNAs play in acute pancreatitis can lead to the development of new diagnostic and prognostic tools for future clinical applications.

Circulating MicroRNAs as Potential Molecular Biomarkers in Pathophysiological Evolution of Pregnancy

MicroRNAs represent nonprotein coding small RNA molecules that are very stable to degradation and responsible for gene silencing in most eukaryotic cells. Increased evidence has been accumulating over the years about their potential value as biomarkers for several diseases. MicroRNAs were predicted to be involved in nearly all biological processes from development to oncogenesis. In this review, we address the importance of circulating microRNAs in different conditions associated with pregnancy starting with the implantation period to preeclampsia and we shortly describe the correlation between placental circulating miRNAs and pregnancy status. We also discuss the importance of microRNAs in recurrent abortion and ectopic pregnancy.

Serum microRNAs as diagnostic markers of endometriosis: a comprehensive array-based analysis

OBJECTIVE

To investigate serum microRNAs (miRNAs) in women with endometriosis.

DESIGN

Case-control study.

SETTING

University hospital.

PATIENT(S)

Women with (n = 24) and without (n = 24) endometriosis.

INTERVENTION(S)

Serum samples were obtained from surgically diagnosed subjects.

MAIN OUTCOME MEASURE(S)

miRNA from women with without endometriosis were used for microarray profiling and confirmed by means of quantitative real-time polymerase chain reaction (qRT-PCR). Receiver operating characteristic (ROC) analysis was performed on differentially expressed miRNAs.

RESULT(S)

miR-3613-5p, miR-6755-3p were down-regulated and miR-125b-5p, miR-150-5p, miR-342-3p, miR-143-3p, miR-145-5p, miR-500a-3p, miR-451a, miR-18a-5p were up-regulated more than 10-fold in the microarray. These results were confirmed with the use of qRT-PCR. Among the differentially expressed miRNAs, miR-125b-5p expression levels had the highest area under the ROC curve (AUC). The maximum AUC score of 1.000 was achieved when combining miR-125b-5p, miR-451a, and miR-3613-5p with the use of a logistic regression model.

CONCLUSION(S)

We identified several miRNAs in serum that distinguished subjects with endometriosis from those without. miR-125b-5p had the greatest potential as a single diagnostic biomarker. A combination of that miRNA with miR-451a and miR-3613-5p further improved diagnostic performance.

Circulating microRNA profile in patients with membranous obstruction of the inferior vena cava

Membranous obstruction of the inferior vena cava (MOVC) is a common type of Budd-Chiari syndrome. However, the pathogenesis of MOVC has not been fully elucidated. Recent studies demonstrated that microRNAs (miRNAs or miRs) are involved in multiple diseases. To the best of our knowledge, specific changes in the expression of miRNAs in MOVC patients have not been previously assessed. The present study used a microarray analysis, followed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) validation, with the aim to access the miRNA expression levels in the plasma of 34 MOVC patients, compared with those in healthy controls. The results revealed a total of 16 differentially expressed miRNAs in MOVC patients. Subsequently, RT-qPCR analysis verified the statistically consistent expression of 5 selected miRNAs (miR-125a-5p, miR-133b, miR-423-5p, miR-1228-5p and miR-1266), in line with the results of the microarray analysis. These 5 miRNAs, which were described as crucial regulators in numerous biological processes and vascular diseases, may play an important role in the pathogenesis of MOVC. Bioinformatics analysis of target genes of the differentially expressed miRNAs revealed that these predicted targets were significantly enriched and involved in several key signaling pathways important for MOVC, including the ErbB, Wnt, MAPK and VEGF signaling pathway. In conclusion, miRNAs may involve in multiple signaling pathways contributing to the pathological processes of MOVC. The present study offers an intriguing new perspective on the involvement of miRNAs in MOVC; however, the precise underlying mechanisms require further validation.

MicroRNA-764-3p regulates 17β-estradiol synthesis of mouse ovarian granulosa cells by targeting steroidogenic factor-1

Previous studies have reported that microRNA-764-3p (miR-764-3p) is one of the most up-regulated microRNAs (miRNAs) in TGF-β1-stimulated mouse ovarian granulosa cells. However, little is known about the roles and mechanisms of miR-764-3p in granulosa cell function during follicular development. In this study, we found that overexpression of miR-764-3p inhibited 17β-estradiol (E2) synthesis of granulosa cells through directly targeting steroidogenic factor-1 (SF-1). MiR-764-3p inhibited SF-1 by affecting its messenger RNA (mRNA) stability, which subsequently suppressed the expression levels of Cyp19a1 gene (aromatase, a downstream target of SF-1). In addition, SF-1 was involved in regulation of miR-764-3p-mediated Cyp19a1 expression in granulosa cells which contributed, at least partially, to the effects of miR-764-3p on granulosa cell E2 release. These results suggest that miR-764-3p functions to decrease steroidogenesis by targeting SF-1, at least in part, through inactivation of Cyp19a1. Taken together, our data provide mechanistic insights into the roles of miR-764-3p on E2 synthesis. Understanding of potential miRNAs affecting estrogen synthesis will help to diagnose and treat steroid-related diseases.

The omniscient placenta: Metabolic and epigenetic regulation of fetal programming

Fetal development could be considered a sensitive period wherein exogenous insults and changes to the maternal milieu can have long-term impacts on developmental programming. The placenta provides the fetus with protection and necessary nutrients for growth, and responds to maternal cues and changes in nutrient signaling through multiple epigenetic mechanisms. The X-linked enzyme O-linked-N-acetylglucosamine transferase (OGT) acts as a nutrient sensor that modifies numerous proteins to alter various cellular signals, including major epigenetic processes. This review describes epigenetic alterations in the placenta in response to insults during pregnancy, the potential links of OGT as a nutrient sensor to placental epigenetics, and the implications of placental epigenetics in long-term neurodevelopmental programming. We describe the role of placental OGT in the sex-specific programming of hypothalamic-pituitary-adrenal (HPA) axis programming deficits by early prenatal stress as an example of how placental signaling can have long-term effects on neurodevelopment.

Noninvasive nucleic acid-based approaches to monitor placental health and predict pregnancy-related complications

During pregnancy, the placenta releases a variety of nucleic acids (including deoxyribonucleic acid, messenger ribonucleic acid, or microribonucleic acids) either as a result of cell turnover or as an active messaging system between the placenta and cells in the maternal body. The profile of released nucleic acids changes with the gestational age and has been associated with maternal and fetal parameters. It also can directly reflect pathological changes in the placenta. Nucleic acids may therefore provide a rich source of novel biomarkers for the prediction of pregnancy complications. However, their utility in the clinical setting depends, first, on overcoming some technical considerations in their quantification, and, second, on developing a better understanding of the factors that influence their function and abundance.

MicroRNA-212 Regulates the Expression of Olfactomedin 1 and C-Terminal Binding Protein 1 in Human Endometrial Epithelial Cells to Enhance Spheroid Attachment In Vitro

Successful embryo implantation requires a synchronized dialogue between a competent blastocyst and the receptive endometrium, which occurs in a limited time period known as the "window of implantation." Recent studies suggested that down-regulation of olfactomedin 1 (OLFM1) in the endometrium and fallopian tube is associated with receptive endometrium and tubal ectopic pregnancy in humans. Interestingly, the human chorionic gonadotropin (hCG) induces miR-212 expression, which modulates OLFM1 and C-terminal binding protein 1 (CTBP1) expressions in mouse granulosa cells. Therefore, we hypothesized that embryo-derived hCG would increase miR-212 expression and down-regulate OLFM1 and CTBP1 expressions to favor embryo attachment onto the female reproductive tract. We found that hCG stimulated the expression of miR-212 and down-regulated OLFM1 but not CTBP1 mRNA in both human endometrial (Ishikawa) and fallopian (OE-E6/E7) epithelial cells. However, hCG suppressed the expression of OLFM1 and CTBP1 proteins in both cell lines. The 3'UTR of both OLFM1 and CTBP1 contained binding sites for miR-212. The miR-212 precursor suppressed luciferase expression, whereas the miR-212 inhibitor stimulated luciferase expression of the wild-type (WT)-OLFM1 and WT-CTBP1 reporter constructs. Furthermore, hCG (25 IU/ml) treatments stimulated trophoblastic (Jeg-3) spheroid (blastocyst surrogate) attachment onto Ishikawa and OE-E6/E7 cells. Transfection of miR-212 precursor increased Jeg-3 spheroid attachment onto Ishikawa cells and decreased OLFM1 and CTBP1 protein expressions, whereas the opposite occurred with miR-212 inhibitor. Taken together, hCG stimulated miR-212, which in turn down-regulated OLFM1 and CTBP1 expression in fallopian and endometrial epithelial cells to favor spheroid attachment.

Circulating miR-200-family micro-RNAs have altered plasma levels in patients with endometriosis and vary with blood collection time

OBJECTIVE

To determine whether circulating micro-RNA (miR) 200a, miR-200b, and miR-141 have altered levels in patients with endometriosis compared with control individuals.

DESIGN

Experimental laboratory study.

SETTING

University.

PATIENT(S)

Patients with endometriosis (n = 61), laparoscopically confirmed endometriosis-free women (n = 35), and self-reported healthy women (n = 30) were included in the study.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Plasma miRNA levels in endometriosis patients and control subjects.

RESULT(S)

We found that the levels of studied miRNAs varied with blood collection time, being lower in the morning than in the evening. When blood collection time was taken into account, the results revealed significantly lower levels of miR-200a and miR-141 in the evening plasma samples of women with endometriosis compared with surgically confirmed disease-free patients. However, the evening-sample levels of all three miRNAs were significantly lower in patients with stage I-II endometriosis than in endometriosis-free control subjects. In cases of stage III-IV endometriosis, only miR-200a levels were significantly lower compared with patients without endometriosis. Circulating miR-200a showed the best discriminative power to differentiate women with endometriosis from patients with similar complaints but without the disease.

CONCLUSION(S)

Our findings suggest that miR-200a and miR-141 have a potential as novel noninvasive biomarkers for endometriosis. In addition, we found that the plasma miR-200a, miR-200b and miR-141 levels vary with blood sampling time, so it is important to take the sample collection time into account when studying miRNAs as biomarkers.

Ionizing radiation-induced microRNA expression changes in cultured RGC-5 cells

MicroRNAs (miRNAs) are a class of short non-coding RNAs that regulate gene expression at the post-transcriptional level. It has been demonstrated that miRNAs serve a crucial role in tissue development and the pathogenesis of numerous diseases. The aim of the current study was to investigate the alterations in miRNA expression in a cultured retinal ganglion cell line (RGC-5 cells) following ionizing radiation injury. Cultured RGC-5 cells were exposed to X-rays at doses of 2, 4, 6 and 8 Gy using a medical linear accelerator. Alterations in cellular morphology were observed under a phase contrast microscope and cell viability was measured using the MTT assay. Subsequent to exposure to X-ray radiation for 5 days, the viability of RGC-5 cells was significantly reduced in the 6 and 8 Gy groups, accompanied by morphological alterations. Total RNA was then extracted from RGC-5 cells and subjected to miRNA microarray analysis subsequent to exposure to 6 Gy X-ray radiation for 5 days. The results of the microarray analysis indicated that the expression levels of 12 miRNAs were significantly different between the 6 Gy and control groups, including 6 upregulated miRNAs and 6 downregulated miRNAs. To verify microarray results, a reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis was performed. The data obtained from RT-qPCR analysis was similar to that of the the microarray analysis for alterations in the expression of the 12 miRNAs. The results of the current study indicated that miRNA expression was sensitive to ionizing radiation, which may serve an important role in mechanisms of radiation injury in retinal ganglion cells.